Enhanced Coffee-Ring Effect via Substrate Roughness in Evaporation of Colloidal Droplets

Figure 4

Evaporation dynamics of a PTFE droplet on a smooth substrate. Panels (a)–(l) correspond to different evaporation times (scale bars represent 100 μm).

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(b)

(c)

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(e)

(f)

(g)

(h)

(i)

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(l)